Maybe it can be like when you body shot it will stick to the players body and detonate after 3 seconds and damage everyone around it and on headshot the damage of the explosion will increase and do more damage.
-stats: The arrow should be much heavier then a normal one so it won't fly as far and you should have only 50% of the ammo. If you taunt it will do the normal stab taunt but when you stab you will get hurt too. :) hope these stats are good comment on this if you think it was bad or good or if you have more suggestions :)